CN-122026043-A - Low-loss coaxial radio frequency cable

Abstract

The application relates to the technical field of radio frequency coaxial cables, in particular to a low-loss coaxial radio frequency cable, which comprises an inner conductor, an insulator and an outer conductor, wherein the insulator comprises a first insulating layer contacted with the outer surface of the inner conductor and a second insulating layer contacted with the inner surface of the outer conductor, the foaming degree of the first insulating layer is more than 60%, the second insulating layer comprises basalt fibers with the content of 1.8-2.5wt% and the foaming degree is 0, the thickness of the first insulating layer is 3-20 times that of the second insulating layer, and the first insulating layer is prepared through physical foaming. The application can improve the cable strength and the operability of the coaxial radio frequency cable preparation while maintaining the cable electrical performance through improving the foaming degree and the strength of the insulating layer.

Inventors

• XU HUI
• CHENG SHUNLI
• HU YUE
• LI JIANJUN

Assignees

• 浙江融汇通信设备有限公司

Dates

Publication Date

20260512

Application Date

20260407

Claims (10)

1. 1. A low-loss coaxial radio-frequency cable comprising: An inner conductor, an insulator, and an outer conductor; The insulator comprises a first insulating layer in contact with the outer surface of the inner conductor and a second insulating layer in contact with the inner surface of the outer conductor; The first insulating layer has a degree of foaming greater than 60%; the second insulating layer comprises basalt fiber with the content of 1.8-2.5wt% and the foaming degree is 0; the thickness of the first insulating layer is 3-20 times of that of the second insulating layer; The first insulating layer is prepared by physical foaming.
2. 2. A low loss coaxial radio frequency cable according to claim 1, wherein said outer conductor is copper.
3. 3. A low loss coaxial radio frequency cable according to claim 1, wherein said first insulating layer has a degree of foaming of 60-80%.
4. 4. The low loss coaxial rf cable of claim 1, wherein the first insulating layer is an insulating layer formed by physical foaming of polyethylene and a nucleating agent.
5. 5. The low loss coaxial radio frequency cable according to claim 4, wherein said first insulating layer is foamed by nitrogen, and the outside radius of said first insulating layer is 3-18mm.
6. 6. A low loss coaxial radio frequency cable according to claim 4, wherein said first insulating layer has an extrusion temperature of 170 ℃ to 190 ℃.
7. 7. The low loss coaxial rf cable of claim 1, wherein said second insulating layer is extruded from a masterbatch of pre-mixed polyethylene and basalt fibers, said basalt fibers having a particle size no greater than 50 microns.
8. 8. A low loss coaxial radio frequency cable according to claim 7 wherein the second insulating layer has an extrusion temperature of 160-170 ℃.
9. 9. A low loss coaxial radio frequency cable according to claim 7, wherein said basalt fiber is silane modified.
10. 10. The low loss coaxial radio frequency cable of claim 1, wherein the first insulating layer and the second insulating layer are extruded in series.

Description

Low-loss coaxial radio frequency cable Technical Field The application relates to the technical field of coaxial cables, in particular to a low-loss coaxial radio-frequency cable. Background The insulating medium of the radio frequency coaxial cable is generally a light-weight high-foaming degree insulating medium formed by physically foaming polyethylene polymers, and has a dielectric constant performance close to that of air (ideal air is 1, and the dielectric constant of the high-foaming degree polyethylene can reach 1.2). The dielectric attenuation and the conductor attenuation are determined by the dielectric constants of the dielectric and the conductor, and thus both the conductor attenuation and the dielectric attenuation are affected by the dielectric constant of the insulating layer. The whole attenuation index of the cable can be improved to a great extent by adjusting the foaming degree of the insulating layer. At present, domestic manufacturers raise the foaming degree to 80-85%, and although the overall attenuation index of the cable is better under the foaming degree, the strength of the cable can be influenced during use at a later stage, such as cell breakage, so that the electrical transmission performance of the cable is influenced. One or more of the foregoing problems have been addressed by the provision of multiple foam layers and increased strength and improved attenuation strength by the skin layer means external to the outer conductor, but such cable manufacturing processes are more stringent with respect to gas injection and bore pressure requirements, thereby increasing costs to some extent. Based on this, there is a need in the art for a radio frequency coaxial cable that has low attenuation and compromise the operability of the manufacturing process to meet the aforementioned needs. Disclosure of Invention At least one aspect and advantage of the present application will be set forth in part in the description that follows, or may be obvious from the description, or may be learned by practice of the subject matter of the application. According to one embodiment of the present application, there is provided a low-loss coaxial radio-frequency cable comprising: An inner conductor, an insulator, and an outer conductor; The insulator comprises a first insulating layer in contact with the outer surface of the inner conductor and a second insulating layer in contact with the inner surface of the outer conductor; The first insulating layer has a degree of foaming greater than 60%; the second insulating layer comprises basalt fiber with the content of 1.8-2.5wt% and the foaming degree is 0; the thickness of the first insulating layer is 3-20 times of that of the second insulating layer; The first insulating layer is prepared by physical foaming. According to one embodiment of the application, the outer conductor is a copper tube. According to one embodiment of the application, the first insulating layer has a foaming degree of 60-80%. According to one embodiment of the application, the first insulating layer is an insulating layer formed by physical foaming of polyethylene and a nucleating agent by gas. According to one embodiment of the application, the first insulating layer is foamed by nitrogen, and the outer radius of the first insulating layer is 3-18mm. According to one embodiment of the application, the extrusion temperature of the first insulating layer is 170-190 ℃. According to one embodiment of the application, the second insulating layer is obtained by extruding a masterbatch of pre-mixed polyethylene and basalt fiber, and the particle size of the basalt fiber is not more than 50 microns. According to one embodiment of the application, the extrusion temperature of the second insulation layer is 160-170 ℃. According to one embodiment of the application, the basalt fiber is silane modified. According to one embodiment of the application, the first and second insulating layers are extruded through a string. The application can improve the cable strength and the operability of the coaxial radio frequency cable preparation while maintaining the cable electrical performance through improving the foaming degree and the strength of the insulating layer. Drawings The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application. Fig. 1 is a schematic cross-sectional structure of a low-loss coaxial rf cable according to an embodiment of the present application. Detailed Description The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those of ordinary skill in the art to better understand and thus practice the teachings of the present application, and are not meant to imply any limitation on the scop